Summary of Off-Normal Events in US Fuel Cycle Facilities for AFCI Applications

Abstract

This report is a collection and review of system operation and failure experiences for facilities comprising the fission reactor fuel cycle, with the exception of reactor operations. This report includes mines, mills, conversion plants, enrichment plants, fuel fabrication plants, transportation of fuel materials between these centers, and waste storage facilities. Some of the facilities discussed are no longer operating; others continue to produce fuel for the commercial fission power plant industry. Some of the facilities discussed have been part of the military's nuclear effort; these are included when the processes used are similar to those used for commercial nuclear power. When reading compilations of incidents and accidents, after repeated entries it is natural to form an opinion that there exists nothing but accidents. For this reason, production or throughput values are described when available. These adverse operating experiences are compiled to support the design and decisions needed for the Advanced Fuel Cycle Initiative (AFCI). The AFCI is to weigh options for a new fission reactor fuel cycle that is efficient, safe, and productive for US energy security. iv v SUMMARYThis report is a collection of historical data on the US fission fuel cycle facilities, focusing on the incidents and off-normal events that have occurred. These data are useful input to the Advanced Fuel Cycle Initiative (AFCI), which is to weigh options for a new fission reactor fuel cycle that is efficient, safe, and productive for US energy security. Only published reports and papers have been researched; no classified or sensitive data were used during this report preparation.The intent of this report is to provide a summary of accidents and events that have occurred in the nuclear fuel cycle for use as operating experience feedback to the design of future fuel cycle facilities that support the commercial nuclear power industry. The nuclear fuel cycle is a mixture of industrial processes. Initially, solution mining that produces the uranium feedstock is an industrial process similar to well drilling in the petroleum industry and it has similar hazards of drilling and pumping fluid. Purifying the uranium solution by solvent extraction is a chemical treatment process similar to different types of ore purification performed in other industries and has the hazards inherent with chemical process plants.Uranium enrichment is performed chemically and mechanically, which in principle is similar to the activities and hazards of the chemical process, petroleum, and other industries. During the enrichment step, nuclear criticality safety concerns begin to arise, which is a complication not found in other industries. Fuel pellet and fuel element fabrication is similar to many manufacturing processes that produce large numbers of high precision parts. Fuel fabrication assembly lines, like those in many industries, are partly automated and partly operated by workers. Uranium fuel has very low radioactivity, so the handling concerns dwell ...

Regulatory cross-cutting topics for fuel cycle facilities.

“…[17], are now the subject of training modules which focus on PRA, Electrical Analysis, Fire Analysis, Human Reliability Analysis (HRA), and Advanced Fire Modeling [5]. This effort, coupled with that of integrating NFPA 805 into the regulatory framework, clearly show the trend towards risk informed decision making in fire protection.…”

Preliminary Failure Modes and Effects Analysis of the US DCLL Test Blanket Module

“…Then a factor of up to 10 would be applied to that result, giving on the order of 0.25 mrem/hour (2.5 PSv/hour), and the required concrete wall thickness would be calculated to reduce the penetrating radiation to that dose rate. The normal operation dose rate to the hot cell equipment operators at EBR-II was typically less than 1 mrem/hour (10 PSv/hour) during the 1960's fuel cycle operations and less than 0.1 mrem/hour (1 PSv/hour) in the more recent operations (Stevenson, 1987;Cadwallader, 2005). The Fuel Cycle Facility hot cell used 1E+06 rem per hour gamma radiation as the typical radiation source (one fuel subassembly).…”